Dog Periods Symptoms. During the first week of pregnancy, the dog eats less food than on normal days. A male dog can impregnate them during this time.
Vulva swelling may become quite noticeable; The earliest sign of heat is swelling of the vulva, but you probably aren’t paying a lot of attention to that part of your dog. A female dog in heat often experiences several symptoms, and one symptom that is often unnerving for dog owners to watch is crying.